Fuel properties of low-erucic acid pennycress (LEAP) oil biodiesel

Abstract

Biodiesel is a renewable biobased fuel obtained from transesterification of plant seed oil with methanol. This fuel has physical properties that make it attractive as an alternative fuel for compression-ignition (diesel) engines. In the United States (US), there is a need to increase the production of sustainable and environmentally friendly biofuels, including biodiesel, to supplement fossil fuels. To meet these challenges, emphasis is being placed on expanding the use of low-cost non-food oils as feedstocks for biodiesel. Low-erucic acid pennycress (LEAP) was developed from field pennycress as a cover crop for use in the Upper Midwestern US. The objective of the present study was to convert LEAP oil to biodiesel (fatty acid methyl esters [FAME]) and evaluate its fuel properties. The same process was applied to FAME made from natural field pennycress (FPC) oil as a baseline for comparison of results. The LEAP oil-FAME (LEAP-ME) had a kinematic viscosity at 40 °C (KV40) that was lower than that of FPC oil-FAME (FPC-ME), and nearly equivalent to the KV40 of soybean oil-FAME (SME). The total saturated-FAME (SFAME) concentration of LEAP-ME (5.40 mass%) was greater than that of FPC-ME. Since SFAME have high melting points, this caused LEAP-ME to have a higher cloud point (CP) than FPC-ME. However, the CP of LEAP-ME (−6.8 °C) was lower than those of canola oil-FAME (CaME; −2.5 °C) and SME (−2.8 °C). The oxidative induction period at 110 °C (IP110) of LEAP-ME was poor (0.83 h), indicating that it would need to be treated with antioxidants before distribution as an alternative diesel fuel.